Adjustable BOV to air/ recirc

[RippinRich]

Way back when I had my WRX I had a fully adjustable BOV which I could adjust any % from either full recirc to full to air. I remember hearing that with the wrx bov to air wasnt really good for the car. Is this similar? Anyone have an adjustable setup like this?

 

[UNBROKEN]

If you have a ‘22 or newer you don’t have a valve. Turbosmart makes a 50/50 valve for the older models that do have a valve. Never seen what you’re talking about on one of these.

 

[TMac]

Those cars used a hot-wire mass airflow sensor (MAF), so measurement was before the turbos. Turbo blow-off valves (BOVs) upset the air fuel ratio (A/FR) since the air was already measured prior to entering the engine. Exhausting it changes the A/FR, and leads to rich mixtures between shifts. The ST uses a more sophisticated speed density system no longer requiring a MAF. BOVs are meaningless in this situation unless you're addicted to sneezing sounds between shifts.

BOVs were a bandaid for '90s turbo,ECU, and airflow measurement technology. I am honestly pleading with people- stop spending money on stuff that makes absolutely no sense, and quit allowing vendors to sell you crap you don't need.

 

[RippinRich]

Ah k intresting, thank you! People will buy meaningless shit till the end of time lol

 

[RippinRich]

Was just told this:

"Sense you have a 22, you do not have a bov at all so there is no recirc, so there is nothing to blow off. This can wear on the turbo thirst bearing overtime. We do suggest upgrading to a bov setup to prevent wear on the turbo."

Do you not agree?

 

[TMac]

Was just told this:

"Sense you have a 22, you do not have a bov at all so there is no recirc, so there is nothing to blow off. This can wear on the turbo thirst bearing overtime. We do suggest upgrading to a bov setup to prevent wear on the turbo."

Do you not agree?

I do NOT agree. Who told you this? A vendor trying to sell you something? Ignorance at its finest. Salesmanship at its worst. Once again, information that was relevant 30 years ago.

Take a look at a post I made some time ago....here

 

[UNBROKEN]

I do NOT agree. Who told you this? A vendor trying to sell you something? Ignorance at its finest. Salesmanship at its worst. Once again, information that was relevant 30 years ago.

Take a look at a post I made some time ago....here

I was gonna answer for you because I already knew…lol

 

[TMac]

I was gonna answer for you because I already knew…lol

I wish you would have beaten me to it! I sometimes get a bit frustrated at the same old BS that some people perpetuate. Thanks.

 

[RippinRich]

Yeah it was a manufacture of cold air intakes / bov charge pipes lol.

Thanks for all the info. As much as Id love to do some mods to this thing ill probably just keep it stock for the warranty.

 

[Greywolf]

Those cars used a hot-wire mass airflow sensor (MAF), so measurement was before the turbos. Turbo blow-off valves (BOVs) upset the air fuel ratio (A/FR) since the air was already measured prior to entering the engine. Exhausting it changes the A/FR, and leads to rich mixtures between shifts. The ST uses a more sophisticated speed density system no longer requiring a MAF. BOVs are meaningless in this situation unless you're addicted to sneezing sounds between shifts.

BOVs were a bandaid for '90s turbo,ECU, and airflow measurement technology. I am honestly pleading with people- stop spending money on stuff that makes absolutely no sense, and quit allowing vendors to sell you crap you don't need.

This is a great explanation and example of useless so-called upgrades. Something similar is aftermarket intakes that are marketed to give you 10 to 15 hp increases. Hell, if this is true, you can get the same amount of horsepower upgrades as the Ford tune for a fifth of the price.

 

[TMac]

While it depends on the car, many people don't realize that due to old-style mechanical wastegates (which can be adjusted to deliver more boost), bleed valves, and manual boost controllers, many manufacturers purposely used undersized or restricted exhausts and intakes to limit boost to make up for the fact that people would monkey with these devices.

It's easy to see that this led to the belief on turbo vehicles that you "had to have" larger intakes and exhausts. Certainly true for some cars but not for all. Certainly not for the ST. If you are using the stock turbos, the stock exhaust and intake is completely capable.

My biggest pet peeve when it comes to intake is when a vendor claims better gas mileage. We're talking part throttle operation at this point- the airflow is already being throttled in some way and in fact is maybe 15% of flow through the filter. So how does even a higher flowing (at 100%) aftermarket intake purport to increase mileage? It doesn't.

 

[UNBROKEN]

While it depends on the car, many people don't realize that due to old-style mechanical wastegates (which can be adjusted to deliver more boost), bleed valves, and manual boost controllers, many manufacturers purposely used undersized or restricted exhausts and intakes to limit boost to make up for the fact that people would monkey with these devices.

It's easy to see that this led to the belief on turbo vehicles that you "had to have" larger intakes and exhausts. Certainly true for some cars but not for all. Certainly not for the ST. If you are using the stock turbos, the stock exhaust and intake is completely capable.

My biggest pet peeve when it comes to intake is when a vendor claims better gas mileage. We're talking part throttle operation at this point- the airflow is already being throttled in some way and in fact is maybe 15% of flow through the filter. So how does even a higher flowing (at 100%) aftermarket intake purport to increase mileage? It doesn't.

That’s not nearly as much fun as the people claiming 4-5mpg increase with a tune. The FB groups are full of them.
Or the guys claiming a HP increase with the Big Mouth snorkel for these things.

 

[TMac]

I was a member of a Subaru website back in the late '90s early '00s- my STI days. I remember one thread having to do with air filters. A user had put a K&N style filter CAI on his car and stated his gas mileage had increased approximately 20%! I posted a response to ask how this would be possible?

He stated it was because prior to changing the filter he was at 3000 rpm when he was at 60 and with the new air filter his rpm had dropped to 2500 at the same speed.

It was obvious to me that he was just making this up to justify his post, so I then made the "mistake" of asking how the heck did an air filter change his final drive ratio? This particular poster had 100s of posts and obviously quite a few friends who thought of him a some kind of "guru". I was then attacked by numerous individuals "defending" the poster. This debate raged for several pages of posts with people putting forward the most unbelievable and physically impossible methods to defend this foolishness.

I stopped posting after that.

 

[TMac]

That’s not nearly as much fun as the people claiming 4-5mpg increase with a tune. The FB groups are full of them.
Or the guys claiming a HP increase with the Big Mouth snorkel for these things.

Oh, yes- the Big Mouth Snorkus. I did a post about the math and realities of that device some time ago. Can't find it now(Edit: found it here) It's worthless. Right up there with a 100 watt computer fan supercharger. Anyone want to tell me how something uses about 1/10 of a kilowatt can add "10-15% more HP and gas mileage"? Once again, worthless.

 

[Greywolf]

I was a member of a Subaru website back in the late '90s early '00s- my STI days. I remember one thread having to do with air filters. A user had put a K&N style filter CAI on his car and stated his gas mileage had increased approximately 20%! I posted a response to ask how this would be possible?

He stated it was because prior to changing the filter he was at 3000 rpm when he was at 60 and with the new air filter his rpm had dropped to 2500 at the same speed.

It was obvious to me that he was just making this up to justify his post, so I then made the "mistake" of asking how the heck did an air filter change his final drive ratio? This particular poster had 100s of posts and obviously quite a few friends who thought of him a some kind of "guru". I was then attacked by numerous individuals "defending" the poster. This debate raged for several pages of posts with people putting forward the most unbelievable and physically impossible methods to defend this foolishness.

I stopped posting after that.

mama always taught me that no question is stupid and is worth asking. Only the ignorant will state otherwise.

 

[Greywolf]

Oh, yes- the Big Mouth Snorkus. I did a post about the math and realities of that device some time ago. Can't find it now. It's worthless. Right up there with a 100 watt computer fan supercharger. Anyone want to tell me how something uses about 1/10 of a kilowatt can add "10-15% more HP and gas mileage"? Once again, worthless.

I agree. I don’t have any issue with somebody wanting to make a change or an upgrade. As long as they understand it’s a novelty change. And with all due respect, you may pick up the tiniest of increased performance, but almost negligible.
An engine is an actual vacuum cleaner. It will suck up as much air as it needs as long as the air intake filter system allows it to. And if the ST already has a filtration system that would allow the max maximum amount of air that the Eco boost would need, at the rate that it needs it why upgrade it. is it just for looks. If so hell my front hood is closed at least 99.99% of the time I am with my ST. So who cares what it looks like under the hood.

 

[TMac]

Finally found my earlier posts on "ram air" as I discussed in post #14. View here and here

Follow those links and you can also find posts from @UNBROKEN on same subject.